Tire-tread.



G. L. RBMPES.

Patented Sept. 7, 1909.

- To all whom it may concern:

UNITED strn'rns cnamnss 1.. nnrrrns, creation, 0310.

' TIRE-Tarzan.

4 s eeimmtn or may Patent.

Patented Sept; 7, 1909;

Application filed nnys, 1967. g 'ser a'l no. 382,654.

' Be it known that I, CHARLES L. Rnmrlis,

a citizen ofthe United States, residing at Akron, in the county of Summit and State of Ohio, have invented a certam new and useful Improvement in Tire-Treads, of which the following is a full, clear, and exact de-.

script-ion.

The object of the present invention is to provide an improved form .of tire tread which shall prevent skidding and afiord an increase in the tractive quality of the "tire.

It is my purpose to accomplish the results desired by means of -a structure which may be readily manufactured at comparatively small expense, but which shall, at the same time, be not only efiicient, but have an endurance and length of life which render it economically possible to use it on heavy machines, such as automobiles. I am aware that this is a field that has been highly developed by experimenters, and I am familiar with the devices which have heretofore been tried for accomplishing the same purposes. But, while some of these have advantages of one sort, they have disadvantages, either as to their method of manufacture or operation, which cause them to fall shortof what I regard as the proper standard of utility.

It has been proposed to roughen the treads of bicycle tires in many diflt'erent ways. Some of these tires, as well as some automobile tires, have been ribbed circumferentially others have been roughened and pitted b having a knurled die wheel run over the rlm while in the mold, a portion of the mold being removed for this purpose. This last method, however, is applicable only to light tires, and the pits made thereby are only useful upon'the theory that they'serve as suction cups, as it is impossible by nurling to displace the rubber to such an extent as to make the rubber between the pits of suiticient mass to serve as resisting projections and thereby increase the tractive effect or prevent si'dewise skidding. This fact has been recognized by the makers of tires, and they have, with this class of bicycle tires, sought to do no more than to' make the divisions between the pits of a thin feather edge, so as to fit asphalt or smooth surfaces and cause the cells or pits to act effectively as suction cups.

As distinguished from the above, and other structures which have been introduced into the art, I have invented a tread having an arrangement of tractive ribs disposed with regard to each other in a unique manner, as will appear by reference to the following specification, and accompanying drawings,in which- 1 Figure l is a plan view showing-a portion of the tread, and Fig. 2 is a section through 3 is a detail section along the line 3-3 of Fig. 1. I

At the tread portion of the tire'A, which .is of the sort ordinarily used in automobiles and adapted to sustain and draw heavy loads, I provide, for a space extending ap-' proximately two inches across the face, diagonally dlsposed ribs B, B making angles of about forty degrees with the central plane of the tire. These ribs are about threeeighths of an inch deep and three-eighths of an inch thick at their bases. I have two sets of ribs oppositely disposed to each other. That is to say, the ribs B of one series are parallel and inclined in one direction, makingan angle of about forty degrees with the plane of the tire, while the ribs B of the same angle to the plane of the tire, but inclined in the opposite direction. The parallel ribs, 'at their nearest oints, are approximately three-quarters of an inch apart. The intervening surfaces C formed by this arrangement are diamond shaped. These angular recesses have all of their tapering walls inclined downwardly toward the center thereof and are disposed with an angle directed longitudinally of the tread, but it is to be particularly noted thatthey are not 'pits or cells formed by nurling tools, since they are broad, substantially flat surfaces, such as can only'be formed by molds. The treadis provided at its outer periphery with nmarallel longitudinally extending tapering side ribs D between which the tapering intersecting ribs extend diagonally from one side rib to the other to'form angular recesses. This is an important point, since it and pits as have been previously made, that they are of an inverted pyramidal o1? hemispherical form with the unfortunate result that any piercing object, such as pins would be directed, by reason of the inclined walls of the cells, to a normal or vertical piercing position in the center of the cell,

even thugh they might have been'lying at the same along the line 2-2 of Fig. 1. Fig.

the other series are likewise parallel and at.

is a particular characteristic of such cells or tacks, lying in the path of the wheel,

some other angle when first encountered. The ribs of my tire, while of course tapered somewhat so asto make them readily ire-' movable from the mold, are spaced widely a art so that the intervening space is, as

.aiove stated, iracticall fiat, except to-tlie extent to whi it con orms to 'tlie gene'ral convex curvature of the tire. By so spacing the ribs apart that the intervening surface is flat, as dist' ished from pyramidal or convex, there beno tendency to guide tacks, nails or similar sharp articles around tofthe normal or vertical position after the manner. of certain. prior structures referred to above.' The formation of the ribs of increasing diameter toward the body of the tread causes them to release clogging matedeep, thick and coarse enough ridges merely thin and flexible. With r15 rial from. the intermediate recesses. When the ribs are in contact with the und and under pressure the diameter of t e recess is decreased b the lateral expansion thereof and when t is pressure is-released the ribs contract to their normal diameter thus releasing any material held in the recesses. Further, by having the ribs s aced widely apart in this manner and by having them to form re? sistant masses, I obtain a gripping action upon the ground and pavement whlch revents sidewise skidding to an extent w ich would be impossible were these dividing I .ribs' of this structure disposed diagon and in opposite directions, after the manner above set forth, the chances of skidding are will appear to those skil reduced a remarkable since the skidding takes place in a sidewise-and forw'ard'direct'ion and it appears that the angle at which therigid ribs are set is ofthe atest importance in overcoming this ten ency. It is obvious also that, in addition to the prevention of the skiddin movement,- the ribs disposed according to t e manner of my invention also increase the tractive quality of the tire, since the resistance of the oppositely disposed diagonal ribs is such as to streets and ordinary roads wlthouttendin to push the tire to either side of the line 0 travel;- These and maniv other advantages ed in' the art. Having thus described my invention, I

claim give the tire a firm'grip upon both asphalt An' annular tire tread havin upon its CHARLES L. REMPES. Witnesses:

H. Rpsunmvan, E. B. GILCHRIs'r 

